Adaptation response of Pseudomonas fragi on refrigerated solid matrix to a moderate electric field

We have conducted a Raman study of methane (CH4), a major constituent of the outer planets, at pressures up to 165 GPa. We observe splitting of the principal Raman-active vibrational mode above 45 GPa and a nonlinear dependence of Raman peak position on pressure. A discontinuous change in the pressure derivative of the ν3 peak position is observed at approximately 75 GPa, corresponding to the phase change previously observed using X-ray diffraction. The Grüneisen parameters for the principal Raman-active modes of methane in the simple cubic and high-pressure cubic phases are calculated. The predicted dissociation of methane at ultrahigh pressure to form C2H6 and H2 is not observed, but an additional discontinuous change in the pressure-induced shift of the Raman peaks is observed at 110 GPa. We suggest that this may be due to some reorientation or reordering of the methane molecules within the framework of the known cubic lattice

Molecular identification of original plants of Fritillariae cirrhosae bulbus, a Tradtional Chinese Cedicine (TCM) using plant DNA barcoding

Background: DNA barcoding is a widely used tool that enables rapid and accurate identification of species based on standardized DNA regions.Materials and Methods: In this study, potential DNA barcodes, namely three plastid regions (rbcL, trnH-psbA and matK) and one nuclear ribosomal internal transcribed spacer (ITS) were adopted for species identification of original plants of Fritillariae Cirrhosae Bulbus.Results: The rbcL and trnH-psbA regions showed better success rate of PCR amplification and DNA sequencing, as well as superior discriminatory ability. On the contrary, ITS region did not possess effective genetic variation and matK was faced with low success rate of sequencing. Combination of multi-loci sequences could improve identification ability of DNA barcoding. The trnH-psbA + rbcL could discriminate 25% - 100% species based on the Blast, Tree-Building and Distance methods.Conclusion: The potential DNA barcodes could not completely solving species identification of botanic origins of Fritillariae Cirrhosae Bulbus. In future, we should pay more attention to super-barcoding or specific barcode that enhance ability to discriminate the closely related plants.Keywords: Fritillariae Cirrhosae Bulbus, species identification, DNA barcoding, internal transcribed spacer (ITS), traditional Chinese medicine (TCM

Nonlinear vibration of hypoid gear with backlash

Due to the machining errors, alignment error, wear, tear and time varying stiffness of hypoid teeth, the vibration of hypoid gears is inevitably produced in the course of working, and its vibration and noise is the main sources of vibration and noise in the automobile transmission. Study on nonlinear vibration and noise of the hypoid gear pair, and investigating on reducing its vibration and noise are of great significance. Firstly, a simplified nonlinear vibration model of the hypoid gears of main reducer, with considering the time-varying teeth stiffness and teeth surface friction damping, was established. Then, a numerical simulation method was employed to simulate different gear backlash effects on the hypoid gear vibration behaviors caused by the gear worn, and effects on the gear non-linear vibration from different work speeds of gear and different loading torques were investigated. In order to help to explain the non-linear vibration phenomenon of the hypoid gears, the 2-D phase plane diagram and the 3-D trajectory were employed. Lastly, the bench test was carried out to verify the simulation results on vibration of hypoid gears with backlash